If it helps, you may wish to think of this progression as consisting of the first half of the progression for Long Journey Home (or Gotta Travel On) followed by the last line of the progression for Wildwood Flower (or Leaning On The Everlasting Arms. or Molly And Tenbrooks).

Other songs that have been played at the jam in which a three-line (as opposed to the much more common four-line) progression is used include Rocky Road Blues, Shuckin' The Corn, Molly And Tenbrooks, and the short form (12 measure) version of Worried Man Blues.

The progression given here is the same as that used for the breaks on the recording (minus extra measures of the 1 that go by between the ending of a break and the beginning of the next verse), but not for the verses. On the recording, there are extra measures of the 1 chord at the ends of both lines 2 and 3 in the verses. I keep the progression the same for both the verses and the breaks (once again, not counting any extra measures of the 1 that I might allow to go by between the ending of a break and the beginning of the next verse).

Form & ArrangementThe arrangement I use for Roving Gambler when leading it at the jam is based upon the recording: seven verses, no chorus, with two verses being sung back to back between breaks, with one verse left over to end the song.

Both the form and the arrangement I use for Roving Gambler are nearly identical with the form and arrangement used on the original Bill Monroe recording of Molly And Tenbrooks, a song that has occasionally been played at the jam, except that Molly And Tenbrooks is sung with 9 verses instead of 7, and makes use of a tack-on ending. See to what extent you can detect the similarities in form and arrangement between the two songs.

A third song with a similar form and arrangement to Roving Gambler and Molly And Tenbrooks is the version of McKinley's Gone (a.k.a., White House Blues) found on Flatt & Scruggs' Folk Songs Of Our Land album:https://www.youtube.com/watch?v=UxD1g2I4FN8

The practical advantage of learning to group songs together based upon similarity of form and/or arrangement is the same as the practical advantage of associating songs with each other that have similar progressions or the same progression as each other. It reduces the number of distinct pieces of information to keep track of when learning new songs, or when trying to follow along on new songs that come up at a jam, and this enables one to more quickly and easily expand one's repertoire.

MelodyThe melody of Roving Gambler consists of the notes of the Major Pentatonic scale which are the 1st, 2nd, 3rd, 5th, and 6th notes of the Major Scale (A, B, C#, E, and F# in the key of A; G, A, B, D, and E in the key of G, etc.) The first two lines (first 8 measures) of the melody of Roving Gambler are similar to the first two lines of the melody of Long Journey Home, except that the melody goes higher in Roving Gambler in measures 3 and 4 of line 1 than what it does in measures 3 and 4 of line 1 of Long Journey Home. The second lines of the two songs are similar enough that I often use exactly the same notes/licks in a melody-based intro break for the second line of Roving Gambler as the ones that I typically use for the second line of an intro break for Long Journey Home. Keep in mind that good melody-based breaks often do not follow the melody slavishly, but take some liberties with it.

HarmonyAlthough Roving Gambler does not have a chorus, it does have repetitions in its lyrics. In these spots, namely, the third (last) line of each verse, it is common for harmony to be sung. The third line of any given verse repeats twice the lyrics that make up the second half of the second line of that verse. (Note: Molly And Tenbrooks has a similar type of repetition at the ends of its verses, but in that song it is not customary for harmony to be sung on the last line of the verses.)